The following is a description of three types of vacuum cleaners which differ in design and operation. All of them have, as common features, a motor-driven fan, a dust collection chamber, and one or more floor treatment devices which are each adapted for a particular purpose.
The canister vacuum cleaner has a housing which can be moved on the floor to be cleaned on wheels and/or runners. The housing contains the motor-fan unit and the dust collection container. The floor treatment device, here referred to as floor nozzle, is connected to the dust collection chamber via a suction hose, and possibly a suction wand connected therebetween. During vacuuming, the housing is moved to the desired position by pulling on the suction wand.
In a stick vacuum cleaner, the motor-fan unit and the dust collection container are also disposed in a housing. A suction wand extends from one end of the housing, connecting the floor nozzle to the dust collection container, and a handle used to maneuver the housing to the desired position extends from the other end.
Uprights do not have as strictly divided a configuration as the two aforementioned types. One feature of an upright is a movable base unit which carries an upper body containing a large dust collection container. The two parts are tiltable relative to each other and can usually be locked in a parked position in which the upper body is nearly upright when the base unit is located on a horizontal floor in a position of use. In this position, which is a locked position in terms of the tilting motion, the upright stands unsupported. During vacuuming, the above-described locked engagement is released, and the upper body is tilted through a certain angle to an operating position. The tilt angle depends on the height of the user and on the particular purpose of use. A handle is provided on the upper body for maneuvering the entire appliance. The upright described in WO 2007/008770 A2, for example, has the drawback that it is difficult to move from a straight path of travel into a curved path of travel. EP 0 708 613 A1 describes providing a point of rotation between the upper body and the upper region of the fan. This enables the upright to move along curved paths, thereby improving maneuverability. If the upper body is then rotated while in the parked position, there is a risk of the upright's center of gravity being moved out of its footprint area, causing the appliance to tip over.